1.25 g of HClO3 is _________ moles of molecules?

See your post above.

To determine the number of moles of molecules in 1.25 g of HClO3, we need to use the molar mass of HClO3 and the Avogadro's number.

The molar mass of HClO3 can be calculated by adding up the atomic masses of its elements:

H (1.01 g/mol) + Cl (35.45 g/mol) + O (16.00 g/mol) x 3 = 85.46 g/mol

Now we can calculate the number of moles using the formula:

moles = mass / molar mass

moles = 1.25 g / 85.46 g/mol
moles = 0.0146 mol

Finally, we can calculate the number of molecules using Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol:

number of molecules = moles * Avogadro's number

number of molecules = 0.0146 mol * 6.022 x 10^23 molecules/mol
number of molecules = 8.80 x 10^21 molecules

Therefore, 1.25 g of HClO3 is approximately 8.80 x 10^21 molecules.

To determine the number of moles of molecules in 1.25 g of HClO3, we will need to use the molar mass of HClO3.

The molar mass of HClO3 can be calculated by summing the individual atomic masses of the atoms in the molecule. The atomic masses of hydrogen (H), chlorine (Cl), and oxygen (O) are approximately 1 g/mol, 35.5 g/mol, and 16 g/mol, respectively.

The molar mass of HClO3 = (1 mol x 1 g/mol) + (1 mol x 35.5 g/mol) + (3 mol x 16 g/mol) = 1 g + 35.5 g + 48 g = 84.5 g/mol

Now, we can calculate the number of moles of HClO3 using the formula:

Number of moles = Mass of Substance / Molar Mass

Number of moles of HClO3 = 1.25 g / 84.5 g/mol

Calculating this equation will give us the answer.